Archive for July, 2008

For million of years after the Big Bang, the universe was a dark place filled only with wisps of hydrogen and helium, as well as the mysterious substance known as dark matter that makes up much of the universe’s mass. Now, researchers have finished running a sophisticated computer program that simulated those early cosmic conditions and replicated the production of the first primordial star, which cast the first rays of starlight out into the blackness. Researchers say that the new model shows that the first star was tiny, but rapidly grew to enormous proportions before either flaming out or collapsing.

In the early universe, researchers believe that clouds of dark matter gathered and compressed pockets of hydrogen and helium gases. According the researchers’ simulation, those areas reached a tipping point around 300 million years after the Big Bang, igniting the first nuclear reactions. Over the course of about 100,000 years, according to the model, the compressed gases reach densities roughly equivalent to that of liquid water on Earth. At that point, the gases inside the halo have formed a protostar, about one-hundredth the mass of the sun [Science News].

Researchers have developed two drugs that mimic some of the effects of exercise in mice, leading to rampant speculation that people may soon be able to take a dose of “exercise in a pill.” The dramatic study showed that the drugs built fat-burning muscles in mice and increased their endurance on an exercise wheel. Four years ago researchers bred genetically engineered mice that could run much further than normal, but this is the first test to prove that drugs can have the same effect [Telegraph].

“It’s tricking the muscle into ‘believing’ it’s been exercised daily,” said the study’s lead researcher, Ronald Evans…. “It’s basically the couch potato experiment, and it proves you can have a pharmacologic equivalent to exercise” [Wired News]. One drug proved effective for mice that were already exercising regularly, increasing their running time by 68 percent and distance by 70 percent. The other drug worked on mice that hadn’t been trained to exercise; that compound increased their running time by 23 percent and distance by 44 percent.

By examining the genetics of snake embryos, researchers have solved a long-standing evolutionary mystery regarding the evolution of fangs on venomous snakes. Researchers have been puzzled because the fangs, which are syringe-like teeth that draw poison from venom glands, have very different placement in different species. Most venomous snakes, including grass snakes, have fangs positioned in the rear of the mouth, while a few groups, including rattlesnakes, cobras and vipers, have fangs jutting down from their upper jaws in the front of the mouth [LiveScience].

Adding to the confusion, researchers had found that the front-fanged snakes aren’t closely related to each other, suggesting that the front-fang trait evolved at least two separate times. The assumption of multiple origins is problematic for evolutionary biologists who prefer to find that complex structures like fangs … don’t just come and go. If they did, fangs presumably would have popped up in other vertebrates [Science News].

In a neat marriage of science and art, researchers used x-rays from a particle accelerator to reveal an early portrait of a woman by Vincent Van Gogh, which the impoverished artist later painted over with a meadow scene. The hidden image bears a striking resemblance to a series of somber portraits the artist produced in the Dutch town of Nuenen, where he composed “The Potato Eaters,” completed in 1885 and regarded as his first major work [Los Angeles Times].

An earlier analysis using conventional x-rays had shown the rough shape of a head hidden beneath the surface of a painting called “Patch of Grass,” but provided no details. To get a clearer image, the researchers used high-intensity x-rays from a particle accelerator in Hamburg, Germany to compile a two-dimensional map of the metallic atoms on the painting beneath “Patch of Grass.”… Knowing that mercury atoms were part of a red pigment and the antimony atoms were part of a yellow pigment, they were able to chart those colors in the underlying image. “We visualized — in great detail — the nose, the eyes, according to the chemical composition.” [researcher Joris] Dik said. Scanning a roughly 7-inch square of the larger portrait took two full days [AP].

A bronze and iron “computer” that the ancient Greeks used to keep track of astronomical phenomena was also a sophisticated calendar that set the dates for the Olympic games, researchers say. The ancient Olympic Games, which marked the start of a four-year timespan called an Olympiad, began on the full moon closest to the summer solstice, which meant calculating the timing required expertise in astronomy [Reuters].

The device is named the Antikythera Mechanism; it was discovered over a century ago in a Roman shipwreck off the tiny island of Antikythera, north of Crete. The mechanism, which was built around 100 B.C., had been reduced to a collection of bronze fragments and gears by its long immersion, but a new analysis has revealed inscriptions beneath the corrosion that name the games of the Olympiad cycle, including “Olympia.”

Two large, international studies have independently found three genetic mutations that are linked to a greatly increased risk of schizophrenia, but say the rare mutations only account for a small percentage of schizophrenia cases. The identification of the three mutations is being hailed as a breakthrough, as no genetic factors had been definitively linked to the disease before. But in a finding of even greater importance, the studies suggest that there’s no easy answer to the question of what causes the devastating mental illness. Instead of a common genetic problem, schizophrenia may be triggered by many rare mutations that cause subtly different variants of the disease.

“What is beginning to emerge is that a lot of the risk of brain diseases is conferred by rare [genetic] deletions,” [study author Kari] Stefansson said…. The new focus on rare mutations suggests that natural selection is highly efficient at removing schizophrenia-causing genes from the population. Despite selection against the disease, according to this new idea, schizophrenia continues to appear because it is driven by a spate of new mutations that occur all the time in the population. [The New York Times].

NASA’s Cassini spacecraft has discovered a liquid lake the size of Earth’s Lake Ontario on the south pole of Titan, Saturn‘s largest moon. Researchers say that Cassini’s instruments reveal that the chilly reservoir … Titan, is composed of a key component of crude oil — liquid ethane [Science News].

The new find supports the common belief that Titan is a promising place to look for extraterrestrial life. Some astrobiologists have speculated that life could develop in the moon’s hydrocarbon lakes, although it would have to be substantially different from known life on Earth, which requires liquid water [Wired News].

The Cassini orbiter has racked up a number of accomplishments since it began investigating Saturn and its moons in 2004, but its most exciting missions have focused on Titan, where the thick nitrogen and methane atmosphere resembles the atmosphere that existed on primordial Earth.

A rocket-powered plane trailing a bright blaze of flame streaked across the Wisconsin sky yesterday, as spectators at the EAA AirVenture air show got the first glimpse of a new sport called rocket racing. But in a setback, the Rocket Racing League wasn’t able to send two rockets soaring into the sky to race against each other as hoped, as the Federal Aviation Administration is still in the process of approving the second aircraft.

[T]he Rocket Racing League is aimed at melding human spaceflight with NASCAR-like competitions in the sky. The racers are designed to belch 15-foot (4.5-meter) flames from their engines that can be easily seen by spectators, and carry limited amounts of rocket fuel to fly through a three-dimensional aerial race course [SPACE.com]. League officials hope to eventually let onlookers follow the planes’ progress through the looping flight path by projecting videos from cockpit cameras onto huge screens, and are also hoping to build a computer game in which players could race against the real pilots.

Researchers have tested a new pharmaceutical approach to combating Alzheimer’s, and say they may have found the breakthrough drug that can halt the progress of the disease. In a small clinical trial, researchers tested a drug that targets the tangles of protein that form in the brain cells of Alzheimer’s patients, and found that the drug stopped the cognitive decline of those patients.

Lead researcher Claude Wischik says: “This is an unprecedented result in the treatment of Alzheimer’s disease. We have demonstrated for the first time that it may [be] possible to arrest the progression of this disease by targeting the tangles which are highly correlated with the disease” [CNN]. The results were announced at the International Conference on Alzheimer’s Disease taking place in Chicago.

A new study may burst the bubble of dinosaur buffs by contradicting an exciting announcement of three years ago: what was earlier identified as soft tissue preserved in the thigh bone of a Tyrannosaurus fossil is actually just modern-day bacteria, researchers say.

The new study challenges the work done by paleontologist Mary Schweitzer, who garnered headlines in 2005 for reporting in the journal Science [that her team] had found the remains of blood vessels inside the fossils unearthed in the Hell Creek Formation in Montana. Finding tissue preserved at least 65 million years shocked paleontologists who believed any such traces were lost forever [USA Today].